Research goals for the coming year include the following: 1) The preparation and measurement of the Mossbauer spectra over a temperature range, of hemochromes with strongly pi-bonding ligands, such as isonitriles, phosphorus trifluoride, and with various sulfur ligands; 2) Measurement of Mossbauer spectra over a temperature range, of four and five coordinated iron (II) prophyrins prepared on a high vacuum line; 3) The preparation and measurement of Mossbauer, infrared and electronic spectra and magnetic susceptibilities over a temperature range, of intermediate to high spin hemichromes with a variety of oxygen and nitrogen ligands and 4) Completion of theoretical calculations on the energy levels and magnetic moments of antiferromagnetic binuclear high spin iron (III) porphyrins.